Merge origin/main: reconcile with PR #92092 (in-checkout launcher restore)

PR #92092 fixed the same vanished-launcher bug by restoring copies into
the legacy in-checkout hermes-agent\bin from the update tail. That
location is what this branch removes: untracked files there are swept
by the update autostash on every cycle (restore/sweep treadmill, plus a
parked stash entry per update under --keep-stash), and unconditional
exe copies break on relocatable venvs ('uv trampoline failed to
canonicalize script path'). This branch's managed-binary-dir layout
supersedes both mechanisms, so the merge resolves to it:

- drop _sync_windows_cli_launchers and its _ensure_acp_launcher call
  (Windows staging/repair lives in ensure_windows_bin_launchers at
  process start and migrate_windows_bin_path in the update tail);
  _ensure_acp_launcher is a Windows no-op again
- keep #92092's genuinely better installer semantics: staging stays in
  a dedicated Install-HermesCommandLaunchers function that throws
  BEFORE any PATH mutation when the required launcher cannot be staged
  and verified -- previously Set-PathVariable could put an empty dir on
  PATH and still print 'hermes command ready'. Reworked for this
  branch's layout: caller passes the destination ($HermesHome\bin),
  launcher form follows the venv (exe copy vs .cmd delegator), and the
  verify step accepts either form
- rework #92092's AST-lifted PowerShell test for the new function
  signature, keeping its fail-before-PATH-mutation assertions and
  adding relocatable-venv form-selection coverage
- drop tests/hermes_cli/test_windows_cli_launcher_repair.py (pinned the
  superseded in-checkout mechanism; equivalent and broader coverage
  lives in tests/hermes_cli/test_ensure_windows_bin_launchers.py)

.gitignore

@@ -98,6 +98,12 @@ apps/desktop/src/**/*.d.ts
 !apps/desktop/src/plugins/*/plugin.js
 !apps/desktop/src/global.d.ts
 !apps/desktop/src/vite-env.d.ts
+
+# Repo-root build/debug artifacts that must never be committed
+/log.txt
+/sqlite_leak_fix.png
+/*.png.bak
+/default.tar.gz
 apps/shared/src/**/*.js
 apps/shared/src/**/*.js.map
 apps/shared/src/**/*.d.ts